This was a calculated and well exercised plan from the start, no debris means the pilot made a water landing keeping most of the aircraft in tact, and drowned the aircraft. He most likely depressurized the cabin before. Why the communication system on the 777 was shut off still baffles me. Had to be deliberate IMO or a fire.
If it was a fire or malfunction and the pilot landed to save lives even temporarily, im sure some if not many passengers would've opted to exit the aircraft as it was sinking, instead of drowning to death.........
Gives me chills just thinking about the horror they would've faced, here's hoping they'll find out more soon!